Comparing values from another database

Hi, I am creating a web registration form using ASP.Net VS2010 & MS SQL Server 2008, where I have fields like Name(Textbox), Surname(Textbox), Date of birth(Calender), Valid Id Type(Which is a dropdown list consists of Passport and Taxcode), Id Number(Textbox), and some other general information fields.
Here I would like to ask you to solve my doubt, that when I press my save button to register this form to my new registration table(db), my webpage must verify the Name, Surname, Valid ID type and ID number from an another table which I already furnished those data. If all those fields are present in the another database then my webpage has to save.
If any field doesn't match to the given, it must throw an error either a validation error or message box or exception.
As soon as the form get successfully registered those details must be deleted from the previous database to reduce duplication.
The Members who are in my previous database only get registered in this database.